JPS6042038B2 - printing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a printing device, which is one of the terminal devices of an information processing system, and particularly to an impact printer.

Conventionally, in this type of printing device, the type of printing paper is automatically detected, and the printing energy is automatically detected by actually performing the printing operation, so that the printing energy is adjusted to be suitable for the printing paper. A printing control system that automatically controls printing energy and maintains good printing quality at all times has not been developed.

Conventionally, a person visually determines the type of print paper, or measures the thickness of the print paper automatically or visually, and then automatically or manually moves the relative position of the platen or the like to the print head based on this. Alternatively, printing energy is controlled to obtain good printing quality by controlling the excitation current of the drive magnet, and the printing energy is detected and controlled based on comparison with the actual printing energy. I haven't done anything like that. If this method relies on human visual inspection, if the printing paper contains multiple sheets of carbon paper, it is easy to misjudge the number of sheets.
Therefore, it is difficult to control the printing pressure accurately.

In addition, it has been known for a long time to directly detect the number of sheets of paper and control the printing energy accordingly, but once the control is set, changes in the operating environment conditions (for example, temperature changes, power supply It is not possible to cope with fluctuations in the clearance between the print head and the platen due to voltage fluctuations or mechanical vibrations, and deterioration of print quality is inevitable. Furthermore, in the conventional method for adjusting print quality, a print sample was determined in advance and the print quality was adjusted based on human senses, so variations in print quality due to individual differences were inevitable. . In addition, in the case of dot printers, the clearance between the platen and the needle is 0.
Since the clearance is extremely narrow (6 to 0.3.-), it is necessary to manually adjust the clearance to 0.05 to 0.1 while checking the printing quality, but this is extremely difficult in practice. This invention was made to overcome the above-mentioned conventional drawbacks, and the printing device according to the invention detects the code attached to the printing paper and controls the printing energy to achieve stable and good results. The purpose is to obtain printing.

This will be explained in detail below with reference to the figures.

FIG. 1 is a block diagram showing an outline of an embodiment of the present invention. In the figure, 1 is a piezoelectric element, 2 is an A/D converter,
3 is a printing energy control circuit, 4 is a usage environment condition judgment circuit, AMP is an amplifier, CPU is a central processing unit, ROM is a read-only memo, and 14 is a reading means for reading the code attached to the printing paper. It is a detector of The piezoelectric element 1 detects the printing energy produced by the needle, and the printing energy detected by the piezoelectric element 1 is sent in the form of electrical energy, amplified by the amplifier AN4P, and then sent to the A/D converter 2. is applied and converted into a digital signal.

On the other hand, the ROM stores a type code that encodes the type of printing paper and a printing energy code that encodes and represents the printing energy for optimal printing according to the type of printing paper. . The CPU reads the print paper type code from the print paper type detector 14, and then outputs the printing energy and energy corresponding to the type code.
The code is read from the ROM, and the digital signal sent from the A/D converter 2 is compared with the printing energy code, and the printing energy control circuit 3 is controlled based on the result. The use environment condition judgment circuit 4 is a circuit for detecting changes in the environment conditions in which the printing device is used and transmitting the detected changes to the CPU. Control 3. Here, if a highly sensitive piezoelectric element 1 is used and the resolution of the A/D converter is improved, the print quality can be determined with precision that cannot be detected by human senses.

For example, if the resolution of the A/D converter is 6 bits, 26=64, so 1164. The printing energy can be detected in units of , and when controlling the excitation current of the electromagnet as a printing energy control means,
If you use a 6-bit D/A converter, 1'? Since printing energy can be controlled in units of , extremely precise control of printing quality can be achieved. In addition, even when using a pulse motor to adjust the clearance between the print head and platen of a dot printer, using a pulse motor with a small step angle will be much easier than manual adjustment that relies on human senses. It is possible to precisely control printing energy.

Fig. 2 shows a flowchart of the operation of printing control according to the present invention, and Fig. 3 shows a flowchart similar to Fig. 2 when detecting changes in usage environment conditions starting from a normal printing operation. This is a flowchart of the operation, and FIG. 4 is a flowchart of the operation of paper feed control.

FIG. 11 is an overall block diagram of a printing device according to the present invention. The overall block diagram of Fig. 11 and the second to fourth
The outline of printing control according to the present invention will be explained in more detail with reference to the flowchart in the figure.

The ROM 13 stores in advance in the same byte the type code of the printing paper and the printing energy code that enables printing with the optimum printing quality for the paper.

Its storage format is as shown in FIG. It is also assumed that the printing paper is composed of a plurality of stacked papers on which formats have been printed in advance.

Its format is as shown in Figure 6a, and Figure a
As can be seen, detection marks M1 and M2 are placed on the side edge of the paper, and if the marks are black, the binary number 1
In the case of white, it is a binary 0, and the type of paper is expressed by the combination of these binary codes.The relationship between the combination of codes and the type of paper is shown in Figure 6b. It is like that. First, by pressing the paper feed key, the printing device is caused to perform a paper feed operation, and the flowchart is shown in FIG.

When the paper feed key is pressed, the key control logic circuit 11 operates, the interrupt control circuit 10 operates, and the CPU is interrupted.
The CPU reads the status information from the key control logic circuit 11 through the data bus, and when it determines that the information indicates that the paper feed key has been pressed, the CPU activates the device selection circuit 8 via the address bus to control the paper feed. Designate circuit 15 and send a paper feed signal from the data bus. C
The PU activates the device selection circuit 8 via the address bus, specifies the printing paper detection circuit 14, and selects the detection mark M.
The presence or absence of M2 is detected. When the paper is fed, the detection mark M1 or M2 on the paper surface is detected by the printing paper detection circuit 14.
information about this is detected in the input/output data
The information is transmitted to the CPU through the bus control circuit 7 and the system control circuit/bus driver 9, and the CPU stops the paper feeding operation. This position on the paper becomes the printing position. In this state, the paper type code (1 in the example in Figure 6a)
0) is read into the CPU and set. This concludes the fourth
The flowchart in the diagram ends. The mechanism for detecting the detection marks M1 and M2 by the printing paper detection circuit 14 is shown in FIG.

Figure 10a shows the relationship between the mark detection sensor attached to the vapor cutter and the printing paper, and the detection marks M1 and M2, and Figure 10b shows the relationship between the mark detection sensor (Y or R) attached to the vapor cutter. A cross-sectional view is shown. As can be seen from Figure b, the configuration of the detection mechanism is as follows. In other words, the light beam from the light emitting element is converged by the acrylic bolt and enters the mark M1 (or M2) on the printing paper. If the mark M1 is black, it is absorbed, and if it is white, it is reflected and hits the light receiving element. reach In this way, mark M1 (or M2) is detected. Next, when the print energy control key is pressed, the input flag in the key control logic circuit 11 becomes 1, and the CP
U is interrupted.

Thus, the CPU enters the flowchart of FIG. CPU
transmits the status information from the key control logic circuit 11 to the input/output data/bus control circuit 7 and the system control/bus control circuit 7.
Upon reading through the data bus via the driver 9 and knowing that the status information is from the print energy control key, the CPU activates the device selection circuit 8 through the address bus to detect the print position detection circuit. 5 and read the A mark and B mark. And A. Based on the results of reading both marks B, the print head control circuit 6 is controlled to adjust the print position. In order to specifically illustrate this relationship, it will be explained with reference to FIGS. 7 and 8.

FIG. 7a is a sectional view of a sensor block used as the print position detection circuit 5, and FIG. 7b shows a code plate for controlling the print position. This code plate H has marks A and B made of opaque parts on its upper and lower tiers. Cross-sectional view of the sensor block 5 (represented by the same reference numeral 5 because it is the same as the position detection circuit) (Fig. 7a)
As you can see, the code plate is inserted through it.
The A mark is read by the combination of the light emitting element A and the light receiving element C in the sensor block 5, and the B mark is read by the combination of the light emitting element opening and the light receiving element 2. Now, regarding marks A and B on the code board E, when they are opaque, they are set to binary 1, and when they are transparent, they are set to binary 0. The print head is fixed to a sensor block 5, and the CPU reads both marks A<5B on the code plate inserted through the block 5, and depending on the result, controls the motor via the print head control circuit 6. drive to control the position of the print head. FIG. 8 shows the relationship between the reading codes of both marks A and B and the horizontal movement of the print head. The position indicated as HP in Fig. 8b is the home position of the print head, and the read code of both marks A and B at this position is 01, and in Fig. 8a
is shown in the rightmost column of the table. Now, assuming that the print head is at a certain arbitrary position, the sensor block 5 fixed to the print head reads both marks A and B on the code plate E, and the result is 11 (column 1 in Figure 8 a). ), then C
The PU drives the motor via the print head control circuit 6 to move the print head to the right, and the sensor block 5 reads both marks A and B on the code plate E when the result is 1.
If it is 0 (2 in FIG. 8a), the CPU drives the motor to move the print head to the left. Even if the reading result of both marks A and B is 00 (3 in Figure 8 a),
Similarly, move the print head to the left. When the print head reaches the home position (HP), the reading result of both marks A and B on the code plate H by the sensor prot 5 at that point is 01 (FIG. 8 a (7) HP column). , this represents the home position, so the CPU ends position control of the print head. In this way, when the print head is located at the home position, the CPU then specifies the print paper detection circuit 14 via the device selection circuit 8 and specifies the paper type code (in the current example, as shown in FIG. 6a). 10) Load. (Note that this operation is omitted if it is completed during the paper feeding operation, as shown in the flowchart of FIG. 4.)a Next, the CPU operates the device selection circuit 8
If the magnet drive circuit 3-1 is specified via , and the N1 magnet is specified, the CPU will:
The N1 magnetic drive command is sent through the system control circuit and bus driver 9 and the input/output data bus control circuit 7.

The printing energy is detected by the excitation of the N1 magnet, and FIG. 9 will be referred to to explain this relationship. FIG. 9 shows a printing energy detection mechanism necessary for printing control according to the present invention. In the figure, ri is a platen, nu is a printing paper, ru is a print head, e is a code plate for head position detection, and 1 is a piezoelectric element. The printing head needle collides with the piezoelectric element 1 by the excitation of the N1 magnet.

As a result, the electrical energy generated in the piezoelectric element 1 represents the printing energy, and this energy is amplified through the amplifier AMP and applied to the control logic circuit and the A/D converter 2, where said energy is It is converted into a binary code (denoted as Ec). The control logic circuit and A/D converter 2 send status information to the CPU that this conversion has been completed. The CPU thereby captures the control logic circuit and the A/D converter 2 via the device selection circuit 8 via the address bus and transfers the energy code (Ec) in this circuit 2 to the input/output data bus control circuit 7 and the system. It is read via the control circuit and bus driver 9. Next, the CPU specifies ROM13 via the address bus, and prints the paper type code (
In the present example, the printing energy code (Ecs) corresponding to 10) is read through the system control circuit and bus driver 9 via the memory data bus. If the two codes do not match, printing energy control is performed. In the flowchart of FIG. 2, control of print energy is accomplished by adjusting the distance between the printhead and the platen. That is, as a result of comparing Ec and Ecs in the CPU, if the CPU determines that Ec<Ecs, the CPU specifies the pulse motor drive circuit 3-2 through the device selection circuit 8 via the address bus, and System control circuit and bus driver 9
and sends a signal through the input/output data bus control circuit 7,
As shown in FIG. 9, move the print head forward (in direction F). Conversely, if it is determined that Ec<Ecs, the pulse motor is similarly reversed to move the print head backward (in the R direction). When determining that Ec=Ecs, the CPU ends the control. With this, the operation of the flowchart of FIG. 2 is completed.
Depending on the sensitivity of the piezoelectric element and the resolution of the A/D converter, Ecl:. If the difference in Ecs is within a certain range, the two may be treated as matched.

Further, as described above, instead of controlling the printing energy by adjusting the distance between the print head and the platen, the printing energy can also be controlled by adjusting the excitation current of the magnet. If the printing paper is plain paper, as is clear from Figure 6b, the reading mark M
Since both M1 and M2 are white, it is not necessary to stop the print paper in front of the mark detection mechanism (FIG. 10) of the print paper detection circuit 14 to read it.

Therefore, when such plain paper is used, the operation using the paper feed key as shown in the flowchart of FIG. 4 becomes unnecessary.
Then, it is sufficient to press the print energy control key from the beginning to cause the CPU to perform the above-described operation. When the power is turned on, the printing paper detection circuit 14 is kept in a reset state, and since the paper type code is 00, a comparison with the printing energy code corresponding to this code is performed using C.
Do PU. Next, FIG. 3 is a diagram showing the flow of the normal printing operation of the printing control according to the present invention, and the normal printing operation will be explained with reference to this flowchart.

First, when you press the print start button, before starting the printing operation,
The CPU checks the number reading devices M1 and M2 of the printing paper detection circuit 14, and if mark 1 is not detected, that is, the paper is plain paper and the type code is 00, so mark 1 is not detected originally. If the paper is not plain paper, but the M1 and dove mark positions on the paper happen to not reach the detection sensor position, the CPU enters the printing program routine.

When mark 1 is detected, the CPU reads the paper type code using the print paper detection circuit 14, and
compares the previously stored paper type code, and if they do not match, the CPU clears the previously stored type code and sets the newly read code. Then, the CPU reads the energy code corresponding to the set paper type code from the ROM, and thereafter performs the same operation as described with reference to the flowchart of FIG. 2. Further, if the paper type code read by the detection circuit 14 matches the paper type code previously stored by the CPU, the CPU sends a message to the device selection circuit 8 via the address bus as the next step. operates to designate the usage environment condition determination circuit 4, and receives status information from the circuit 4 through the input/output data bus control circuit 7 and the system control circuit/bus driver 9 to determine whether or not there is a change in the usage environment conditions. If it is determined that there is no change, the printing program routine begins. If it is determined that there is a change, C
The PU reads the stored print energy code corresponding to the paper type code from the ROM, and thereafter performs the same print energy control operation as when the print energy control key is pressed. Thus, the flow of operations shown in FIG. 3 is completed. As explained in detail above, this invention
Since the printing energy is variably controlled using the code attached to the printing paper, it has the outstanding effect of automatically producing clear printing even when the printing paper is changed. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an overview of an embodiment of the present invention, FIG. 2 is a flowchart of the operation of printing control according to the invention, and FIG. When detecting changes in environmental conditions,
4 is a flowchart of the operation of paper feed control, FIG. 5 is a diagram showing the storage format of information in the ROM, FIG. 6 a shows the format of the printing paper, and b shows the detection A diagram showing the relationship between mark code combinations and paper types; FIG. 7a is a cross-sectional view of the sensor block; FIG. 8b is a diagram showing a code plate for controlling the print position; FIG.
9 shows the combination of the codes of both marks A and B on the code plate, b shows how the position of the print head is adjusted with respect to the code plate, FIG. 9 shows the printing energy detection mechanism, and FIG. 10 a
11 shows a detection mechanism for a detection mark on printing paper, b shows a sectional view of a detection sensor, and FIG. 11 shows an overall block diagram of a printing apparatus according to the present invention.

In the figure, 1 is a piezoelectric element, 2 is an A/D converter, 3 is a printing energy control circuit, 4 is a usage environment condition judgment circuit, and A
MF' is an amplifier, CPU is a central processing unit, ROM is a read-only memory, 14 is a print paper type detector,
E is the code plate, A and the light emitting element, C and 2 are the light receiving elements, R is the platen, N is the printing paper, L is the print head, Y is the vapor cutter, D and R are the mark detection sensors, and S is the mark detection sensor. The light-emitting element, T indicates an acrylic ball, and N indicates the light-receiving element.

Claims (1)

[Claims] 1. A code reading means for reading the code attached to the printing paper, a storage means for storing a printing energy code representing the printing energy in relation to the code attached to the printing paper, and a printing energy code from the storage means. 1. A printing device comprising a printing energy control means for variably controlling printing energy by using a code attached to printing paper to control printing energy.